Zeta potential in sandpacks: Effect of temperature, electrolyte pH, ionic strength and divalent cations
File(s)
Author(s)
Vinogradov, Jan
Jackson, Matthew D
Chamerois, Manuel
Type
Journal Article
Abstract
Rocks in many subsurface settings are at elevated temperature and are saturated with brines of high ionic strength (high salinity) containing divalent ions. Yet most laboratory measurements of zeta potential in earth materials are obtained at room temperature using simple monovalent electrolytes at low ionic strength. Consequently, the zeta potential at conditions relevant to many subsurface settings is not known. We report experimental measurements of the temperature dependence of the zeta potential in well characterised, natural quartz sandpacks over the temperature range 23–120 °C saturated with electrolytes containing divalent ions at a range of concentrations relevant to natural systems. We find that the key control on zeta potential in these unbuffered experiments is pH, which varies in response to temperature and electrolyte composition. The zeta potential is negative irrespective of sample or electrolyte, but its magnitude is strongly correlated to pH, which varies both with temperature and the concentration of divalent ions. The pH decreases with increasing temperature at low ionic strength, but is independent of temperature at high ionic strength. The pH is also typically lower in the presence of divalent ions, irrespective of the total ionic strength. The zeta potential increases in magnitude with increasing pH. Different relationships between zeta potential, temperature and concentration of divalent ions could be obtained in buffered experiments where the pH is fixed at a given value.
Date Issued
2018-09-20
Date Acceptance
2018-05-16
Citation
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2018, 553, pp.259-271
ISSN
0927-7757
Publisher
Elsevier
Start Page
259
End Page
271
Journal / Book Title
Colloids and Surfaces A: Physicochemical and Engineering Aspects
Volume
553
Copyright Statement
© 2018 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Total E&P UK Limited
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000436459800033&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
4300003006
Subjects
Science & Technology
Physical Sciences
Chemistry, Physical
Chemistry
Zeta potential
Sandpacks
Temperature/pH/composition/concentration/ divalent
Controlled (low)
salinity waterflooding
OIL-RECOVERY
SANDSTONES
SILICA
COEFFICIENT
EXPLORATION
INJECTION
TRANSPORT
VOLCANO
SURFACE
IMPACT
Publication Status
Published
Date Publish Online
2018-05-19